Pacific Ocean air traffic system fails

A newly installed Federal Aviation Administration air traffic control system that helps controllers track and separate planes flying over the Pacific Ocean went down for almost 16 hours earlier this month forcing controllers to rely on other techniques to track aircraft.

The system that broke down was the Interim Situation Display (ISD) which gives oceanic air traffic controllers at the Oakland Air Route Traffic Control Center in Fremont Calif. a visual display of aircraft flying over the Pacific Ocean. It replaced 1960s equipment with updated display channels controller workstations and network infrastructure.

The FAA considers ISD which was installed in the Oakland center in November to be operational but it is not considered fully integrated with the air traffic system yet.

Tony Greer the National Oceanic Procedures representative for the National Air Traffic Controllers Association who was working during the outage said it occurred when the FAA tried to upgrade the ISD software during routine maintenance.

"When I came to work it had already been down for eight hours " Greer said. "If this was a domestic problem it would have shut down airports. By percentages it was a pretty safe operation but it was very stressful for all involved."

However the outage did not affect the safety of about 500 planes flying over the ocean the FAA said.

Backup Measures

Controllers rely on three methods—one of which is ISD— for separating and tracking planes over the Pacific Ocean. When ISD went down Greer said he and other controllers were forced to rely on a so-called conflict probe which sends alerts if planes fly too close to one another and progress reports sent by pilots via radio that are then written down on strips of paper by the controller.

ISD is scheduled for installation this year in the New York Center which covers aircraft coming from the Caribbean and South America.

With ISD controllers use a 20-inch square color monitor that displays information graphically instead of the older round radar displays that are black and white. However much of the back-end equipment such as the IBM Corp. mainframe which the displays are connected to is still old Greer said. "A lot of our limitations are caused by how the [old mainframe language] and the hardware interact " he said.

Raytheon Co. is the prime vendor on ISD. Company officials could not be reached for comment.